Direct Ethanol Production from Lignocellulosic Materials by Mixed Culture of Wood Rot Fungi Schizophyllum commune, Bjerkandera adusta, and Fomitopsis palustris

Abstract

The cost of bioethanol production from lignocellulosic materials is relatively high because the additional processes of delignification and saccharification are required. Consolidated bioprocessing (CBP) simultaneously uses the multiple processes of delignification, saccharification, and fermentation in a single reactor and has the potential to solve the problem of cost. Some wood-degrading basidiomycetes have lignin- and cellulose-degrading abilities as well as ethanol fermentation ability. The white rot fungus Schizophyllum commune NBRC 4928 was selected as a strong fermenter from a previous study. The lignin-degrading fungus Bjerkandera adusta and polysaccharide-degrading fungus Fomitopsis palustris were respectively added to S. commune ethanol fermentations to help degrade lignocellulosic materials. Bjerkandera adusta produced more ligninase under aerobic conditions, so a switching aeration condition was adopted. The mixed culture of S. commune and B. adusta promoted direct ethanol production from cedar wood. Fomitopsis palustris produced enzymes that released glucose from both carboxymethylcellulose and microcrystalline cellulose. The mixed culture of S. commune and F. palustris did not enhance ethanol production from cedar. The combination of S. commune and cellulase significantly increased the rate of ethanol production. The results suggest that CBP for ethanol production from cellulosic material can be achieved by using multiple fungi in one reactor.

A detailed overview of xylanases: an emerging biomolecule for current and future prospective

“…It has the capability of converting xylan directly to ethanol. Horisawa et al (2019) suggested direct ethanol production from lignocellulosic materials by consolidated bioprocessing using the mixed culture of wood rot fungi, i.e., Schizophyllum commune, Bjerkandera adusta, and Fomitopsis palustris.…”

Hypoxia is regulating enzymatic wood decomposition and intracellular carbohydrate metabolism in filamentous white rot fungus

“…It is thus likely that these organisms temporarily tolerate microaerophilic to anaerobic growth environments by switching to fermentative metabolism while they decompose wood. In fungi, production of ethanol by sugar fermentation is apparently a conserved trait that is not restricted to only the Ascomycota yeasts like Saccharomyces cerevisiae [12,13].…”

The anaerobic survival mechanism of Schizophyllum commune 20R‐7‐F01, isolated from deep sediment 2 km below the seafloor

“…Ethanol is the second important metabolite produced by fungi (e.g., A. nidulans , A. fumigatus , S. cerevisiae ) as an alternative electron acceptor to recycle NAD(P) + under anaerobic conditions (Shimizu et al ., 2010; Grahl et al ., 2011; Horisawa et al ., 2019). RNA‐seq analysis also demonstrated that fungi produce ethanol by up‐regulating the genes involved in glycolysis in response to a low level of molecular oxygen (Setiadi et al ., 2006; Askew et al ., 2009; Masuo et al ., 2010).…”